A telecommunication system is described which comprises at least a first and a second end station. The first end station enables intruding on the second end station if the latter is in a busy mode by sending an intrude message to the second end station. The second end station is configured for reproducing...http://www.google.ca/patents/US6047057?utm_source=gb-gplus-sharePatent US6047057 - Telecommunication system intruding on a busy called party
